Compressor



May 14, 1957 R. C. HUDSON ET AL 2,792,170

COMPRESSOR Filed June 29, 1955 werf 052%@ n @45.

6 Claims. (Cl. 2330-196) The present invention relates to a compressorcomprising a pump barrel and a plunger for supplying air under pressure,and more particularly to a novel plunger and cup-like packing assemblyadapted to be reciprocated in the pump barrel and when the plungerreaches the limit of its forward movement the packing is expanded insuch manner as to maintain the leather or composition of the packingsupple and to prolong its life or period of usefulness, as well asassure optimum effectiveness in operation.

Among the objects of 'the present invention is the provision of a novelcup-like packing mounted on the end of a plunger or piston rod in suchmanner as to be springbiased toward expanded position.

A further object of the present invention is the provision of a novelmeans and manner of detachably mounting a cup-like packing on the end ofa plunger or piston rod whereby the packing may be quickly and easilyassembled, removed or replaced, all without the necessity or use of anytools.

The present invention further comprehends the provision in a compressoror pump assembly of a detachable cup-like packing and a resilientmounting for retaining the cup-like packing in assembled relation, andwhen assembled this mounting functioning also to expand or spring-biasthe annular ange of the packing in such manner as to maintain it incontinuous wiping and sealing Contact with the interior of the pumpbarrel.

ln the present embodiment, the forward or discharge end of the barrel orpump cylinder is flared or enlarged to receive and maintain the liangeof the packing expanded beyond the normal internal diameter of thebarrel by a plurality of spring fingers or resilient projectionsarranged in spaced relation on the retaining member or mounting.

Further objects are to provide a construction of maximum simplicity,efiiciency, economy and ease of assembly and operation, and such furtherobjects, advantages and capabilities as will later more fully appear andare inherently possessed thereby.

In the drawings:

Figure l is a view iu side elevation of one form of compression sprayerin which is shown embodied the present novel compressor, a portion ofthe tank or container of the sprayer being broken away to show the lowerend of the pump barrel or cylinder of the compressor and in dottedoutline its plunger rod and pump packing.

Fig. 2 is a fragmentary enlarged View in 'vertical cross section throughthe lower end of the pump barrel and the novel plunger or pistonassembly, including the novel means and manner of detachably mountingthe cup-like packing on the lower or inner end of the plunger or pistonrod and maintaining the sealing flange of this cup-like packing expandedin conformity with the internal diameter of the pump barrel or cylinder,the view showing the end of the plunger rod and the cup-like packingnear the end of the compression stroke and spaced from the discharge endof the pump.

Fig. 3 is a fragmentary enlarged View similar to Fig. 2

l 2,792,170 Patented May lll, E?

but showing the cup-like packing moved to approximately the limit of itsforward or compression stroke, or when the pump is not in operation, atwhich time the flanged end of the packing is expanded in conformity withthe enlarged diameter of the pump barrel.

Fig. 4 is a View in horizontal cross section taken in a planerepresented by the line 4-4 of Fig. 2 and viewed in the direction of thearrows.

Fig. 5 is a view in horizontal cross section taken in a planerepresented by the line 5 5 of Fig. 2 and viewed in the direction of thearrows.

Fig. 6 is a bottom plan view of the detachable mounting for the cup-likepacking and showing its circumferentially spaced spring lingers orprojections for spring-loading or spring-biasing the flanged end of thecup-like packing toward expanded position.

Referring to the detailed disclosure in the various views of the drawingin which the present invention is embodied in a compression sprayer 10,it is to be understood that the present novel compressor is not limitedthereto but is adapted to and comprehends employment in various types ofsprayers or wherever a compressor or pump is required or adaptable foruse.

The compression sprayer lil includes a tank or container il adapted toreceive a substantial quantity of a liquid or spray solution to besprayed or dispensed through a discharge tube or outlet i2. Mounted inthe tank is a compressor or pump i3 including a pump barrel or cylinderi4 of substantially uniform diameter throughout the greater portion ofits length and at its discharge end flared or expanded outwardly at l toprovide a portion of somewhat greater diameter.

ln the illustrative embodiment, the pump barrel ld at its discharge endis provided with an end cap lo having a depressed central portion i7provided with an opening or discharge passage for the air underpressure, and an outwardly and forwardly dared or tapered wall i8 havingits flanged outer end i9 press-tted into and suitably anchored orsecured within the end i5 of the pump barrel. A hollow and externallythreaded plug Zi (Fig. 2) is secured in the opening in the depressedcentral portion i7 and adapted to receive a housing 22 for a pump valve23 spring-biased toward closed position by a spring 24. This valve 23carries a gasket 25 adapted to be moved into sealing engagement againsta tapered lip of a valve seat 26. The valve housing 22 is provided withone or more discharge openings 27 for the passage therethrough of air onthe compression stroke of the pump at which time the Valve 23 is openedagainst the expanding or compression spring 2d.

Mounted on the end of a plunger or piston rod 2S is a cup-like packing29 having 'a depending or outwardly projecting dared portion or annularflange 31 adapted to be maintained in continuous wiping and sealingcontact with the interior wall of the pump barrel or cylinder ifi as theplunger rod 28 is reciprocated by its handle 3l) for supplying air underpressure to the interior of the tank -or container l1. The cup-likepacking 29 is provided with a relatively large, centrally disposedopening adapted to receive a central embossment on a washer 32 aixed tothe plunger rod 28 at a point spaced from its lower or inner end $3 andalso affixed to this end of the plunger rod but in spaced relation withthe washer 32 is a substantially smaller washer 34.

To detachably mount the cup-like packing 2S onto the end of the plungerrod` 28 and also to retain the flange 3l thereof expanded against theencompassing internai wall of 'the pump barrel or container id is asubstantially cup-shaped retainer 35 having a key slot 36 in the basethereof extending from the center of the retainer to adjacent itsflanged periphery 37. This slot adjacent the center of the retainer isof a size and contour to conformably receive the portion of the plungerrod between the washers 32 and 34, and the enlarged offset portion 38 ofthe slot 36 being of a size or di-ameter as to conformably receive thewasher 34, after which lateral move ment of the retainer 35 and thecup-like packing 29 carried thereby causes the smaller and centrallyarranged opening of the slot 36 to be received about the plunger rod 23and thereby locate the cup-like packing 29 in its proper centeredposition on the plunger rod 28 with the base or diaphragm 39 of theretainer 35 received and anchored between the spaced washers 32 and 34.

The anged periphery 37 of the retainer is formed or provided with spacedresilient tongues or projections 41 exerting a continuous expandingforce `or pressure against the annular flange 31 of the cup-like packing29 where by to spring-bias and maintain this flange in contact with theinternal -cylindrical wall of the pump barrel or container lid. In orderto most effectively prolong the life of the cup-like packing, which isgenerally of leather although it may be of `any exible material orcomposition suitable for the purpose, the cylinder is expanded at oradjacent its end to provide thereat yand between it and the flared wallof the end cap an annular and outwardly directed space adapted toconformably receive the llange 3i. of the cup-like packing 29 and expandit beyond the normal internal diameter of the cylindrical part of thepump barrel 14. Thus at the end of the compression stroke or when theplunger rod is moved to the position shown in Fig. 3, the cup-likepacking is expanded beyond the normal internal diameter of the barrel.

Having thus disclosed the invention, we claim:

l. ln a :compressor having a pump cylinder, a plunger having a pair ofspaced washers mounted adjacent an end of the plunger with the lowermostwasher of smaller external size than the other, a cup-like packinghaving an opening therein, and a retainer mounted in the cup of thepacking and provided with a key slot having an enlargement -ofset fromthe center thereof and of a size to receive the lowermost washer,whereby the opening in the packing and the offset enlargement in theslot of the retainer may be slipped over the smaller washer and when theretainer is moved laterally into the space between the washers they areautomatically anchored onto the plunger.

2. In a compressor, a pump cylinder having an enlarged wall portion atits discharge end, a plunger and `a cup-like packing in said cylinderhaving a continuous ange in contact with the internal wall of thecylinder and a central opening through which said plunger projects, andretaining means for mounting the packing upon the end of the plunger,said means including an enlargement on the end of the plunger, a washeron said plunger spaced from said enlargement, and -a retainer providedwith resilient means for maintaining the packing ange expanded intocontact with the internal wall of the cylinder and with the enlargedwall portion as the plunger approaches the end of the compressionstroke, said retainer having a key-hole slot with the enlarged portionof the slot offset from the center of the retainer and of a size toreceive the enlargement on the end of the plunger whereby the retaineris slipped over the enlargement on the end of the plunger and movedlaterally into detachable connection with the plunger.

3. in a compressor, a cylinder providing an air chamber with the wall ofthe cylinder flared outwardly at the discharge end, a plunger adapted tobe reciprocated in said cylinder and carrying a cup-like packing having-an opening and an annular sealing ange in contact with the internalwall of the cylinder, and -a resilient mounting retaining the packing onthe plunger and maintaining the ange of the packing expanded against theinternal wall of the cylinder and against the lared end of the cylinderat the end of the compression stroke, said plunger having a washerprovided with a depressed central portion adapted to be received in saidopening in the cup-like packing and an enlargement on the inner end ofthe plunger spaced from said first mentioned washer to receive thepacking and resilient mounting therebetween. the opening in said packingbeing adapted to be slipped over the enlargement on the yend of theplunger and located over the depressed portion of said washer, and saidmounting having a key slot with the enlarged portion of the slot olisetfrom the center of the mounting and `of a size to receive theenlargement on the plunger whereby this mounting is slipped over theenlargement on the end of the plunger and moved manually intointerlocking engagement with the plunger above said enlargement fordetachably retaining the packing in xed position.

4. .Tn a compressor, a pump cylinder having an enlarged wall portion atits discharge end, a plunger and a cup-like packing in `said cylinderhaving a continuous annular flange in contact with the internal wall ofthe cylinder and a central opening through which said :plunger projects,a removable retainer for detachably 4mounting the packing on theplunger, said retainer having resilient projections for maintaining thepacking iiange expanded into contact with the internal wall of thecylinder and with the enlarged wall portion as the plungerapproaches theend of the compression stroke, and means for detachably mounting theretainer on the end of the plunger including an enlargement on the endof the plunger and a member spaced from said enlarge- `ment forcentering the packing on the plunger and a key-hole slot in the retainerwith the enlarged portion of the slot offset from the center of theretainer and of a size whereby the retainer is slipped over theenlargement and moved laterally into interlocking engagement.

5. In a compressor, a cylinder providing a pump barrel and having anoutwardly iiared wall pontion, a plunger adapted to be reciprocated inthe cylinder, a cup-like packing detachably mounted on the end of theplunger having an opening to receive the end. of thc plunger and aflange in contact with the interior of the cylinder as t-he plunger' isoperated, a retainer for detachably mounting the packing on the end ofthe plunger and provided with tension means for expanding the ange ofthe packing against the outwardly flared wall portion of the cylinder asthe plunger approaches the end of its compression stroke and therebyprolonging the life of the packing, and means for detachably mountingthe retainer on the end of the plunger including an enlargement on theend of the plunger, a washer on said plunger spaced from saidenlargement with the packing mounted between said washer and saidenlargement, and a key-hole slot in the retainer, the enlarged end ofthe key-hole slot being odset from the center of said re tainer and of asize -to receive the enlargement, whereby when the retainer is slippedover the enlargement on the plunger and the retainer moved laterally,the smaller end of the keyhcle slot conformably receives the plungerabove said enlargement.

6. In a compressor, a pump cylinder of substantially uniform diameterthrough the greater portion of its length and adjacent its discharge endhaving its wall flared outwardly beyond the normal diameter of thecylinder, a plunger adapted to be reciprocated in the cylinder, acup-like packing having an opening to receive the inner end of theplunger and having its peripheral .rim in contact with the cylinder, are ainer for detachably mounting the packing on the inner end of theplunger and provided with resilient projections for expanding theperipheral rim of the packing against the flared portion of thewall andbeyond the normal diameter of the cylinder as the plunger approaches theend of its compression stroke, and means for detachably mounting saidretainer and packing centered on the inner end of said plunger, saidmeans including an enlargement on the inner end of said plunger and anabutment spaced from said enlargement and between which the packing ismounted, and a key slot in said retainer having the enlarged p0rtion ofthe slot offset from the center of the retainer and of a size to =beslipped over said enlargement `and the retainer moved laterally intointerlocking engagement with the plunger.

References Cited in the file of this patent UNITED STATES PATENTS IngramAug. 30, 1921 Andrews Oct. 10, 1922 Hallauer Aug. 14, 1923 Marks Aug. 7,1928 Seyforth Sept. 17, 1935 Smith Feb. 7, 1950 FOREIGN PATENTSSwitzerland Nov. 30, 1938 Germany Apr. 9, 1951

